Bictegravir-based treatment wins in HIV/HBV co-infections

MONTREAL — For individuals infected with both HIV and hepatitis B virus (HBV), the choice of virus-suppressive therapy to use can make a difference in outcomes, as evidenced by the 48-week results of the Phase III ALLIANCE results.

In a head-to-head comparison, fixed doses of bictegravir, emtricitabine, and tenofovir alafenamide (Biktarvy) or dolutegravir, emtricitabine, and tenofovir disoproxil fumarate were both able to control HIV in the vast majority of patients (95% versus 91%, P=0.21), reported Anchalee Avihingsanon, MD, PhD, of the Thai Red Cross AIDS Research Center in Bangkok.

But bictegravir-based therapy was superior in suppressing HBV at 48 weeks, Avihingsanon said in her presentation at the International AIDS Conference.

Among 241 adults co-infected with HIV-1/HBV who initiated first-line antiviral therapy, 63% of patients on bictegravir-based regimens reduced HBV DNA levels to less than 29 IU/mL compared to 43.4% of patients on dolutegravir-based regimens (P=0.0023).

She called the bictegravir-based regimen “a safe and effective treatment” for this patient population, adding that both treatment options were well tolerated in ALLIANCE.

Avihingsanon noted that twice as many patients taking the bictegravir formulation had hepatitis B surface antigen (HBsAg) seroconversion compared to patients taking dolutegravir therapy (23% versus 11%), although the difference was not statistical reached significance.

By week 48, liver enzymes had normalized in 73.3% of patients on bictegravir compared to 55.3% of patients on dolutegravir (P<0.05), she reported.

“Chronic hepatitis B affects about 8% of people living with HIV, and the HIV/hepatitis B virus co-infection rate can reach 25% in areas where both viruses are endemic,” Avihingsanon said, adding that these patients are a have higher risk of cirrhosis and liver cancer than people with HBV infection alone.

People with these coinfections should receive treatment to suppress both viruses, she stressed.

Current international guidelines recommend the following:

• Before starting antiretroviral therapy, all individuals who test positive for HBsAg should be tested for HBV DNA with a quantitative assay to determine the extent of HBV replication

• Because emtricitabine, lamivudine and tenofovir disoproxil fumarate have anti-HIV and HBV activity, when HBV or HIV treatment is required, antiretroviral therapy with the combination of tenofovir/emtricitabine or tenofovir/lamivudine as the backbone of a nucleoside analogue reverse transcriptase inhibitor should be initiated fully suppressive antiretroviral regimen should be initiated

• When HBV treatment is required and tenofovir is unsafe to use, entecavir is the recommended alternative treatment option in addition to a fully suppressive antiretroviral regimen

Avihingsanon noted that both tenofovir disoproxil fumarate and tenofovir alafenamide are approved for treatment combinations, but until the ALLIANCE trial, regimens containing these nucleotide reverse transcriptase inhibitors had not been compared in a clinical trial with subjects with the co-infection who initiate treatment.

ALLIANCE recruited patients internationally, but most heavily in Thailand, China and Malaysia (88% of participants were Asian). The mean age of the patients in the study was 32 years. Only 9% of patients on bictegravir were female at birth, as was 2% of patients in the dolutegravir arm. Mean CD4-positive cell counts were approximately 240 cells/ml.

To be eligible for the study, HIV viral load at diagnosis had to be at least 500 copies/mL, HBV DNA at least 2,000 IU/mL, and patients had to have good renal function.